638105400 has 144 divisors (see below), whose sum is σ = 2173588560. Its totient is φ = 167731200.

The previous prime is 638105393. The next prime is 638105401. The reversal of 638105400 is 4501836.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638105401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 125304 + ... + 130296.

It is an arithmetic number, because the mean of its divisors is an integer number (15094365).

Almost surely, 2^638105400 is an apocalyptic number.

638105400 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638105400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1086794280).

638105400 is an abundant number, since it is smaller than the sum of its proper divisors (1535483160).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

638105400 is a wasteful number, since it uses less digits than its factorization.

638105400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5086 (or 5074 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 638105400 is about 25260.7482074463. The cubic root of 638105400 is about 860.9226621806.

The spelling of 638105400 in words is "six hundred thirty-eight million, one hundred five thousand, four hundred".